I think of it as having a nice set of 256 “registers”, in the zero page at addresses 0-255. I think of the A register as kind of an intermediate location for data that is going from memory to the ALU or the ALU to memory. The article says as much:

> In effect the 6502’s ‘page zero’ in memory provides a large number of ‘pseudo’ 8 and 16-bit registers, slower than real registers, but still faster and more versatile than having to use other parts of memory. A skilled programmer making effective use of ‘page zero’ could write code that was fast when compared to other 8-bit designs.

I haven’t done a lot of 6502, though. I learned Basic on the Apple II when I was young but moved to Think Pascal, HyperCard, and CodeWarrior on the Mac.